The present invention is directed to vehicle controls and to control systems which are adjustable and include a number of manual actuators associated therewith. In particular, the vehicle control is for use with motor graders.
In the operation of heavy equipment, such as construction equivalent, tractors, road graders, logging machinery, etc., a number of manually operated actuators are provided on a steering column or adjacent a steering column which are used by the operator for controlling various functions of the machine. Controls of this type typically adjust hydraulic control values and its is preferable to have a lever arrangement which provides a mechanical advantage for adjusting the control valves as is now the case. It is also preferable to have actuators which move easily, are sensitive to movement and considered light to actuate.
The control arrangement, including the steering wheel and actuators, should be adjustable to accommodate different operators and different operating positions. This is particularly important in road graders where, due to the diversity in operations of the grader and the varying degree of accuracy, the operator may choose different operating positions.
In operating heavy construction equipment, a further consideration is the operating visibility and the cabs of the vehicles are designed to increase visibility. The control systems of the prior art partially obstruct this visibility as can be appreciated in considering the structure disclosed in U.S. Pat. No. 3,737,003 and Reissue U.S. Pat. No. Re. 31,646.
Pedestal mount steering columns are normally mounted on the center line and do not substantially obstruct visibility. Visibility can be improved by maintaining the width of the pedestal relatively narrow. Any cables or linkage arrangements should be in close proximity to the pedestal, however, for operator ease, the actuators must be spaced from the center line of the pedestal a much greater distance. The control console should take into account the host of operating positions and the physical requirements for the operator to control the grader by means of the hand and foot controls.